In the related art, as a bearing for a high-speed rotating body, a radial bearing, which is used to be externally attached to a rotary shaft, is known. As the radial bearing, a radial foil bearing is well known, which includes a thin sheet-shaped top foil which forms a bearing surface, a back foil which elastically supports the top foil, and a cylindrical bearing housing which accommodates the top foil and the back foil. As the back foil of the radial foil bearing, a bump foil, in which a thin sheet is formed in a wave shape, is mainly used.
In the radial foil bearing, in order to prevent the top foil or the back foil from being detached from the bearing housing, one end (toe portion) of the top foil or the back foil is directly fixed to the bearing housing or is indirectly fixed thereto via a spacer, using spot welding.
Moreover, as a structure to perform a mechanical fixation instead of the fixation using the welding, a structure, in which the end of the top foil or the back foil (bump foil) is bent and the bent portion is engaged with an engagement groove formed in the bearing housing, is also known (for example, refer to Patent Documents 1 to 3).